I find dueling in Tribes base to be highly competetive, and insanely fun, I haven't played a fps that I would consider superior.
I don't play very often anymore, but that's because of the lack of people to compete against.
Tribes is one of those rare gems that never dies, is addicting (To some) and overall fun.
I agree fully, A good tribes duel is very challenging. Aswell as a good tribes teamwork based Match.
Only thing, is that to me, tribes is slowly dying... I've had too many issues/situations/things-to-do to play tribes anymore. My schedule now, ranges from 6:15 AM to 9:30 PM. 3 Hours breaktime in between. So, I just don't have time to play anymore.. I used to play TRPG, aswell as Anni, Bio, Shifter, and other cool mods... But once a stressful situation would arise, I would be too tense to play, and overall loose skill. I play once in awhile... But it's just not the same for some reason....